I was surprised it etched it so quickly. Maybe I didn't get it fast enough? I thought it was on there no more than 10 minutes. I didn't hear the cat do it so I'm not sure how long it was. Are there any type of sealers that can stop citrus, stomach, or other types of acid, at least for a while?
Here are the images of the travertine (not the damaged pictures -- just showing what it looks like):
Home Construction - a photoset on Flickr